In order to study the effects of the supply pressure and temperature of oil on the diffusion angle and volume flux of jet oil sprayed by nozzles of gear cases

both the two phase and single phase flow models of the jet flow field of three dimensional nozzles were simulated by employing the Large Eddy Simulation based on the FLUENT. The rationality of the simulation results of the two phase and single phase flow models of jet flow field of three dimensional nozzles was demonstrated by the diffusion angle and volume flux of jet oil measured by the method of high speed visualization and weighting jet oil

respectively. The diffusion angle of jet was approximately zero within the scope of 100 millimeters along the axis apart from the exit of nozzle when the ratio of length to diameter was greater than 2 and the angle between the axis of nozzle orifice and the axis of upstream flow channel changed in the range of 0 to 90 degree. The volume flux of jet oil increased as the orifice diameter

the angle between orifice axis and upstream axis increased and as the orifice axial length decreased. The result indicate that the diffusion angle of jet is not affected in actual working conditions when the ratio of length to diameter is greater than 2 and the angle between the axis of nozzle orifice and the axis of upstream flow channel changes in the range of 0 to 90 degree. Both the local loss and the linear loss are influenced by the change of the orifice diameter

the orifice axial length and the angle between orifice axis and upstream axis

finally leading to variation of volume flux of jet.